HS, meaning horizontally set, refers to how prongs secure a synthetic spinel gemstone parallel to the setting. This allows light to freely enter for maximum radiance and sparkle. By not obstructing the crown, HS settings showcase synthetic spinel's optical performance. The discreet prongs spotlight the stone itself. Simple solitaires or elaborate halos suit HS synthetic spinel stones. Round, cushion, emerald cuts and more look stunning when horizontally set.